javascript problem

hi there
thank you for helping me before but i have new problem with javascript i need to disable the selection list wheb the checkboxes are unchecked and enable when they are checked
this my code so far

So, what doesn't seem to be working? Start off with a minimalistic approach rather than trying to incorporate the functionality into your existing complicated code. Use an excellent Firefox addon Firebug to debug your Javascript. You can view the Javascript errors in Firebug as well as Firefox's Error console [Tools -> Error console].